Loading platform light fixture

ABSTRACT

A conventional light fixture having a protective shield which absorbs impact and destructive forces and flexible coupling which avoids forces which it cannot withstand.

United States Patent Marsh [4 Dec. 26, 1972 [54] LOADING PLATFORM LIGHT [56] References Cited FIXTURE UNITED STATES PATENTS [72] Inventor: Anthony Marsh, 51 Revere Street,

Hun Mass. 02045 3,193,674 7/1965 Flemmg ..240/73 8] X 22 Filed; 12, 1970 Primary Examiner-Samuel S. Matthews Assistant Examiner-Richard A. Wintercorn [21] PP 88,822 Attorney-Richard F. Benway 52 US. Cl .240/54 A, 240/73 BJ, 240/102 [57] ABSTRACT [51] Int. Cl ..F2lv 15/00, F2lv 21/00 A conventional light fixture having a protective shield [58] Field of Search ..240/73 BI, 73 BA, 54 A, 102 which absorbs impact and destructive forces and flexible coupling which avoids forces which it cannot withstand.

4 Claims, 4 Drawing Figures LOADING PLATFORM LIGHT FIXTURE This invention relates to light fixtures but more particularly to light fixtures that are used on loading platforms. Trucks usually back up to platforms and take on or unload cargo. The platform is usually small because materials cannot be stored on a platform without protection from the weather and/or theft. Accordingly, immediately adjacentto the platform are overhead doors. These doors must be rolled up out of the way when the trucks are being loaded or unloaded. Truck depots and receiving stations operate at night and on days when ambient light is limited; furthermore, security requires that loading or receiving stations do not have an overabundance of windows which can be easily broken. The doors must also be significantly heavy. Therefore, some form of artificial light must be provided such that the area immediately adjacent the platform and within the truck vehicle will be illuminated to facilitate the unloading and loading of the vehicle.

A very popular device used in loading trucks under discussion above are called pallet loaders. The pallet loader must be able to drive into and out of the vehicle when the doors are open. A light fixture then which is useful in this application must be placed within the building where power is available. Furthermore, the light fixture must be able to extend out beyond the building in order to illuminate the platform area and the interior of the truck body. Movement of the truck or pallet loader and the slamming closed of the overhead doors can strike and destroy an ordinary light fixture so disposed. Light fixtures so used have a very 7 short life span.

The present invention combining several features is able to resist these destructive forces, for it absorbs initial impact and rolls out of the way of forces it cannot withstand. Prior art devices transmitted the-initial impact to the lamp causing the filament or the glass envelope to break. The present invention diverts this impact to the arm away from the lamp and a movable member is then put in motion to slide the lamp holder and entire fixture out of the way.

Therefore an object of the present invention is to provide a light fixture for use on loading platforms having auseful life span.

Another object of the present invention is to provide a light fixture having initial impact absorbing qualities as well as the ability to move out of the way of destructive forces.

Other objects, advantages and features of the present invention will be better understood from the following specification, especially when read in connection with the attached drawing of which,

FIG. 1 is one-half of a double-light fixture, in accordance with the present invention;

FIG. 2 is a loading platform;

FIG. 3 is a single fixture; and FIG. 4 is a double fixture.

Referring now to FIG. 1, we see the basic elements of the present invention, even through only one half of a double light fixture is shown. Normally the light fixture is placed between two doors and each light extends out from one side and illuminates an adjacent truck. The light is mounted about 4 to 6 feet from the floor so that itcan be manipulated easily by a person of average height.

Base plate 26 is shown bolted firmly to the wall and is very rigid. Portion 22 is also a rigid member. The electrical wiring extends through 22 and designated 28 and eventually wired to a source of electric power within the building. Attached to rigid member 22 is a universal joint pivoting about points 25 and 24. The unit therefore can move in any direction up, down, left or right a very important part of the invention. However, the universal joint alone cannot solve all the destructive problems one encounters in such light fixtures.

Pivots 24 and 25 are adjustable and are spring loaded. Universal joints are well known in the art and will not be discussed further. With reference to the present application, (a light fixture) they are seldom considered. For that matter, in the prior art they have. never been used in such an application. The universal connection as will be seen more fully is essential, for when the light fixture encounters a pallet loader or truck, it must move out of the way in order to avoid being crushed or destroyed.

An extension member 21 slightly longer than rigid member 22 is also shown. The reason-for its being longer is to provide the light with an ability to extend outside the building around a corner.

A commercially available lamp holder 1 1 is mounted rigidly onto member 21. The lamp within this fixture 11 may or may not have shock mountings. lt has been found in practice that shock mountings along are not satisfactory for they do not prevent damage. A rough service lamp is also recommended, however, filament breakage is not often the problem. The filament, of course, must withstand some vibration and impact and a well structure filament is therefore useful in the present application. However, it alone is unsatisfactory for its life expansion is extremely short in actual practice.

The inventor therefore has provided a shield or protector for the critical lamp holder 11. it was found necessary to provide a special shape, which took the initial impact or shock and directed it to arm 21 at point 19, which is the only firm or positive connection that the protector is provided with. I

This protector has two rings. The rings are of different diameters. One ring 13 having the larger diameter and 12 having the smaller diameter. The large diameter ring is located ahead of the lamp holder. The lower diameter ring is located immediately in back of the lamp holder 11. These rings are constructed of heavy-gauged steel. This steel is structually very stiff and its round shape provides considerably additional strength. The steel utilized in this situation is approximately one eighth inch in thickness and approximately three quarter of an inch in width. The diameter of the ring will be related to the size of the lamp holder. The lamp holder in any event must be somewhat smaller in order to be adequately protected by this protector.

A /Q inch margin of protection that is, if the lamp holder 11 does not come within /2 inch of any of the steel structure of the protector, the light fixture will be entirely protected. The rings are tied together by approximately inch round stock as shown in 15, 16 and 14. These rods are of a different type of steel from the rings, preferably they are a soft hot rolled steel. When they are welded to rings l2, l3 and clamp 19, they form a resilient overall protector. The angle that these suplOM) l 2 0433 porting components make with the lamp holder and its supporting arm are extremely important.

An important aspect of this invention is to absorb initial impact. Inasmuch as the fixture must have some inertia when a pallet loader or motor vehicle strikes it, some means of absorbing this impact must be provided. Accordingly, the protector provides aflexibility and resilience which takes up the shock of this initial contact with the motor vehicle or the like, the light fixture accelerates, i.e., starts moving, overcoming the inertia, the universal joint takes over and will move out of the way of the motor vehicle or other impact-producing mechanism.

Another important factor in the protector is the angle that the structural components make with the lamp holder. If the lamp holder makes a director or normal contact with the motor vehicle or door, a crushing force could develop. However, if the door or the motor vehicle struck at an angle, the force would be somewhat deflected and the light fixture would roll out of the way and not be destroyed or crushed. Accordingly, the rods forming the protector 18, 17, l6, l5, l4 and so forth are at an angle. If the unit is struck from any direction, the force is directed to the arm and the light fixture merely rotates or turns or moves out of the way.

The initial impact which causes the protector to move slightly is transferred to the arm at point 19 where it is clamped to member 20, therefore, no shock is translated to the lamp holder and/or the lamp therein which would cause the glass or filament to be broken.

With the present invention, the life of the lamp contained within the light fixture is extended by several orders of magnitude over anything in the prior art. Impact is diverted, shock is absorbed, and crushing forces are avoided with the present invention.

Referring now to FIG. 3, we see base plate 26 and one-half of the fixture. We also note lamp holder 11 can swing 90 degrees to illuminate the entire truck body interior.

Referring now to FIG. 4, we see the two halves of the light fixture together on their base plate 26, again the lamp holder 11 is able to swing freely in any direction.

In FIG. 2, two overhead doors are shown with base plate 26 between them and two lamp holders 11 located on either side. A door if it comes down and comes in contact with a light fixture merely pushes it down, the angular bars then cause the light fixture to start rotating causing its universal connector to move such that the light is turned inwardly and out of the way by the time the door gets downto a position where it is closed.

Therefore, as we have seen, if the light fixture is struck hard with a quick blow, the protector tr anslates this initial impact to the arm of the light fixture. We also note that the force which can cause a crushing force on a firmly'fixed light fixture is avoided by the universal connector or joint halfway up the .light fixtures arm. Furthermore, aprotector over the lamp holder which contains the actual lighting unit translates lam contained therein.

Athough l have described my invention with reference to particular apparatus, those skilled in the art may make so many substitutions and variations without departing from its true scope and spirit, I therefore wish to be limited only by the appended claims, of which:

lclaim:

l. A loading platform light fixture comprising in combination with overhead doors,

a rigid member,

means for affixing said rigid member toa stationary structure of a loading platform,

a movable member, 7

a universal connector between said rigid member and said movable member,

' a lamp holder affixed to said movable member,

a lamp holder'protector including, I

a first ring having a diameter at least one-inch larger than the largest diameter of said lamp holder,

a second ring having a diameter less than one-half the diameter of said first ring and no less than one-half inch larger'than the smallest diameter of said lamp holder,

a clamp for connecting said protector to said movable member about six inches behind the point of connection of said lamp holder to said movable member,

structural members interconnecting said rings and clamp,

said rings and clamp so disposed with reference to one another, said structural members form an angular relationship not normal to the lamp holder or the movable member thereby forming a roll-bar cage about the entire lamp holder.

2. A loading platform light fixture as claimed in claim 1, wherein said rings are stiff steel having a thickness of at least one-eighth inch and a width of about three quarters of an inch.

3. A loading platform light fixture as claimed in claim 2, wherein said structural members are fabricated from round soft steel stock having about one-quarter inch in diameter.

4. A loading platform light fixture as claimed in claim 3, wherein said universal joint includes means for adjusting the tension between movable and fixed members. 

1. A loading platform light fixture comprising in combination with overhead doors, a rigid member, means for affixing said rigid member to a stationary structure of a loading platform, a movable member, a universal connector between said rigid member and said movable member, a lamp holder affixed to said movable member, a lamp holder protector including, a first ring having a diameter at least one-inch larger than the largest diameter of said lamp holder, a second ring having a diameter less than one-half the diameter of said first ring and no less than one-half inch larger than the smallest diameter of said lamp holder, a clamp for connecting said protector to said movable member about six inches behind the point of connection of said lamp holder to said movable member, structural members interconnecting said rings and clamp, said rings and clamp so disposed with reference to one another, said structural members form an angular relationship not normal to the lamp holder or the movable member thereby forming a roll-bar cage about the entire lamp holdEr.
 2. A loading platform light fixture as claimed in claim 1, wherein said rings are stiff steel having a thickness of at least one-eighth inch and a width of about three quarters of an inch.
 3. A loading platform light fixture as claimed in claim 2, wherein said structural members are fabricated from round soft steel stock having about one-quarter inch in diameter.
 4. A loading platform light fixture as claimed in claim 3, wherein said universal joint includes means for adjusting the tension between movable and fixed members. 